function [x,y,h] = plot_quality(data_file, linestyle, quality)
    a = load(data_file);
    x = [];
    y = [];
    for i=quality
        n = find( a(:,5) <= i , 1, 'first');
        if ~isempty(n) 
            x = [x a(n,5)];
            y = [y a(n,2)];
        end
    end
    h=semilogx(x,y,linestyle,'LineWidth',2); hold on
    %loglog(x,y,linestyle,'LineWidth',2); hold on
end
